Harvest Tart of Red Onion, Greens and Grapes ...

Katie shared another recipe with me, from her favorite cookbook, The Splendid Table's How to East Supper: Recipes, Stories, and Opinions from Public Radio's Award-Winning Food Show, by Lynne Rossetto Kasper and Sally Swift. She's very innovative in her cooking choices and has a good sense of what will work for her ... and what won't! This tart was delicious!
SUPPER TART OF RED ONION, GREENS AND GRAPES
1 light-packed cup mixed salad greens (spring mix or baby romaine)
A generous 1/2 cup good tasting seedless grapes
1 medium red onion, sliced into 1/4-inch-thick slivers
Shredded zest of 1/2 large lemon
1 large garlic clove, fine chopped
Leaves from 5 fresh thyme sprigs
1 tablespoon good tasting extra-virgin olive oil
Generous 1/4 teaspoon salt
1/8 teaspoon fresh-ground black pepper
2 sheets frozen puff pastry, defrosted (one 17.3 ounce package)
1/4 cup heavy whipping cream
1 cup shredded Asiago cheese
1. Set one oven rack as low as possible. Preheat the oven to 500 F. Tear the greens into bite-sized pieces as you add them to a large bowl. Toss them with the grapes, onion, lemon zest, garlic, thyme, olive oil, salt and pepper.
2. On a large ungreased cookie sheet, lay out the pastry sheets side by side so they overlap by 1/4 inch. Press the overlapping edges together to seal. Create a rim by folding the pastry edges up and over on themselves and pinching them together. You'll end up with a rectangle that is about 7-1/2 x 17 inches.
3. Fill the center of the tart with the vegetable-grape mixture, spreading it out so there is space between the pieces. Slip it onto the bottom rack of the oven, and bake 15 minutes. As the tart bakes, blend the heavy whipping cream and the cheese.
4. Remove the pan from the oven. Spoon the cheese mixture over the tart, spreading it out. Slip it back into the oven to bake another 6 minutes, or until the cheese is melted and barely picking up color. Pull the tart from the oven. Let it stand a few minutes, then cut it into 8 squares. Serve it right away or at room temperature. Although best eaten the day it's made, this tart does reheat well in a pinch.